Descartes

“In the beginning…”

Although René Descartes is often called the “father of modern philosophy,” he has been attacked, reviled, and condemned like no other thinker for most of the last 350 years. Even Pope John Paul II has recently felt the need to criticize him. Refutations continue to pile up. European philosophy is haunted by Descartes and his ideas. One of his most important ideas is his rationalism, that is, that the human mind makes a major contribution to knowledge by means of innate ideas. The mind is understood to be structured by a range of principles which are not derived from sense experience. Sense experience may be required to “trigger” aspects of our mental structures, but sense experience alone cannot yield knowledge. That, in turn, generates an account of human nature. Rationalism is usually taken to stand in opposition to empiricism, the view that all our knowledge is derived from sense experience. Empiricism generates a very different theory of human nature. These two different doctrines about human nature generate considerable controversy, much of it both fierce and bitter. In the pages that follow I shall briefly provide some historical background. Then the core of Descartes’s philosophy will be formulated. Finally, some of the factors behind the controversy, and the primary reasons why Descartes became the primary target of criticism over the last three and a half centuries will be explored.

First, a few biographical words on Descartes’s background. He was born into a family of the minor aristocracy on 31 March 1596 at La Haye (now Descartes!) in Touraine, France. His mother died in May 1597 and he was raised in the home of his maternal grandmother (who died in 1610). He does not seem to have had a close relationship with his father.

His father had little sympathy with Descartes or with what he achieved, and is reported as having said, on the publication of Descartes’ first book, the Discours and accompanying essays, in 1637 “Only one of my children has displeased me. How can I have engendered a son stupid enough to have had himself bound in calf?”1

He studied at La Flèche (founded in 1604), one of the schools which the Jesuits had recently established as part of their intellectual defense of Catholicism against the ideas generated by the Protestant Reformation. Scholarships were available for intelligent but financially poor boys, a practice which enhanced the intellectual level of the student body. It was under this rubric that Marin Mersenne (1588–1648), who would become Descartes’s best friend, attended La Flèche. Descartes’s father had money, so he was able to take advantage of the option of having a private room. A cousin, Etienne Charlet SJ, was on the staff and became rector in 1608 (later appointed an assistant to the General of the Jesuit order). Descartes entered La Flèche in 1606 and left in 1615 at the age of nineteen. After completing his studies, he qualified in law at the University of Poitiers, but did not work at it. Instead, he served in non-combatant roles in the army of Maurits of Nassau (1567–1625), spent some time traveling, and resided in Paris before moving to The Netherlands in 1628 where he remained for twenty years. Descartes, it should be noted, had the good fortune to have received a comfortable inheritance and hence was never pressed for funds.

In 1649 he accepted an invitation from Queen Christina of Sweden (1626–89) to tutor her in his philosophy. Descartes had always been a very late riser (even at La Flèche), but the Queen nevertheless scheduled their discussions for five in the morning. He caught pneumonia and died on 11 February 1650, a cautionary tale philosophers have always taken seriously! Descartes was a traveler in life and his body was a restless traveler in death. It was first moved to France in 1666 and then transferred to several other locations in Paris. In due course it was reburied (1819) in the chapel of the Sacré Coeur in the church of St. Germain-des-Prés. Along the way, Descartes’s skull was removed and replaced with another! There were also problems with Descartes’s papers after his death. A friend shipped them from Sweden but the ship carrying the chest containing his manuscripts sank just outside of Paris. His good friend, Claude Clerselier, rescued the chest and then spent days drying out the pages and reassembling them. They included several volumes of correspondence plus the texts of Treatise on Man (1662), The World (1664), and the Treatise on the Formation of the Foetus (1664).

By any standard, Descartes was “present at the creation” of the new science, that mechanization of the world picture to which, among others, Copernicus (1473–1543), Johann Kepler (1571–1630), Galileo (1564–1642), Isaac Beeckman (1588–1637), Marin Mersenne (1588–1648), Robert Boyle (1627–91), Gottfried Wilhelm Leibniz (1646–1716), and Isaac Newton (1643–1727) all contributed in major ways. As a young mathematician, Descartes was instrumental, at a very early age, in the development of analytic geometry. His success in developing an extremely abstract algebraic representation of geometry, thereby minimizing its apparent empirical basis, seems to have deeply affected his thinking about both science and philosophy. His work on inertia and motion contributed directly to the new mechanical physics whose explanatory power did so much to drive Aristotelian science from the scene, although within a generation, Cartesian physics, which did not allow action at a distance, was displaced by Newton’s own more powerful account. Descartes also wrote on optics, especially on the law of refraction, despite the fact that Willebrod Snell (1580–1626) had formulated, but not published, the law some years earlier. Descartes tried to discover how blood circulated before William Harvey (1578–1657) produced his own largely definitive solution (1628), at which point Descartes proceeded to defend Harvey’s account.

Descartes seems to have acquired his knowledge of science from his wide circle of friends, first in Paris and then in The Netherlands. He matriculated at the University of Franeker in 1629 and a year later in Leiden but we seem to know little about his studies. Franeker is located in Friesland and in Descartes’s day was a major university, but its university status was suppressed by Napoleon. Descartes took lodgings initially in the castle of a Catholic family. It provided him with easy access to where he could attend mass.2 Over the years, Descartes lived in many parts of The Netherlands and established a wide circle of friends (and critics!). Many French people lived for extended periods in The Netherlands (often because of the persecution of the Huguenots) and, generally like English speakers, did not bother to learn the language. This was true even in the 1680s when large numbers of Huguenots were given refuge. Descartes, however, was an exception. Accompanied by a manservant, he was traveling (1621) in a small private craft from Emden en route to West Friesland. The crew, thinking he was a rich foreigner, plotted to rob him. Overhearing them, Descartes immediately drew his sword and told them, in Dutch, that he would kill them if they made any trouble. He thus passed a language test with high stakes!3 In the sixteenth, seventeenth, and for much of the eighteenth century, Latin was the universal language of philosophy, science, and theology. Descartes could read, write, and speak Latin, as could his English, French, and Dutch contemporaries.

The Netherlands was the center of European science in the seventeenth century, and not surprisingly was hence the birthplace of the Enlightenment.4 The decentralized nature of the Dutch government and the wide diversity in religious opinion made it difficult to suppress the printed or spoken expression of dissident views. Hence a variety of philosophical, scientific, and theological ideas, both orthodox and heterodox, were to be seen and heard. Democratic political ideas as well as arguments on behalf of religious toleration quickly took hold, side by side with the theocratic ideas found among the more orthodox Protestants. Comfortable as he may have been in The Netherlands, he returned to France in 1647 hoping for the recognition which he nevertheless felt had eluded him in The Netherlands. His affairs in Paris did not turn out to his satisfaction: “The innocence of the desert [The Netherlands] from which I came pleases me much more [than Paris] and I do not believe I shall be delayed from returning there in a short time” (letter to Chanut, May 1648). In August 1648 he returned to The Netherlands.

Turning now to more philosophical matters, we are told that Descartes met Isaac Beeckman in 1618 in Breda, The Netherlands. By that time Beeckman had for some years been working on topics which Descartes was beginning to explore. More to the point, they were both looking at the world as mathematical physicists. The sophistication which Beeckman brought to questions in algebra, and geometry, and his analyses of such notions in mechanics (physics) as motion, rest, and falling bodies greatly stimulated Descartes’s own thinking. This shift to the use of mathematical models was of course one of the hallmarks of the New Science. Beeckman was generous to a fault to Descartes. He provided ideas, he put his vast scientific knowledge at Descartes’s disposal, and corrected likely mistakes. He appreciated that Descartes was a difficult person, but even he may have been surprised to find Descartes, in later years, accusing him of plagiarism.

The strict separation of science from philosophy had not yet developed but the education that Descartes received at La Flèche was in some measure scholastic. That is, the texts and the arguments to which Descartes would have been exposed were in part rooted in the work of such medieval Christian thinkers as Duns Scotus (1265–1308), William of Ockham (1290–1349) and Thomas Aquinas (1225–74). Their theological and philosophical stands were grounded in various ways on Aristotle’s views, at least as Aristotle’s ideas had been filtered through several centuries of discussion. Islamic philosophers such as Averroes (1126–98) and Avicenna (980–1037) and Jewish thinkers like Moses Maimonides (1138–1204) were also major contributors to the mix.

It is not clear how thoroughly Descartes was immersed in scholastic thought. In a technical sense, scholasticism simply means the “philosophy of the schools,” the philosophy which developed in the universities, primarily Paris but also Oxford, in the period from the twelfth through the fifteenth centuries. The philosophy was itself largely a set of variations on the philosophy of Aristotle. Presumably Descartes was acquainted with at least some of the writings of Augustine, Bishop of Hippo (354–430), Duns Scotus, William of Ockham and Thomas Aquinas. And he clearly was familiar with the writings of the Spanish Jesuit, Francisco Suárez (1548–1617), often described as the last of the scholastics.

The primary focus of Descartes’s philosophy was not scholastic in nature. Instead, he was influenced by scientific concerns of the New Science and the threats to that science posed by scepticism. The principle literary source for scepticism as a systematic philosophy is Sextus Empiricus. But before we turn to Sextus Empiricus and the arguments of the Pyrrhonians, a few other historical details are in order. Although manuscripts of Sextus’s writing must have been stored in one or another of the libraries in the Mediterranean area including those in Byzantium, his views made little impact on the major figures of the medieval period. They were interested in problems of knowledge and certitude, the nature of the world, and the processes whereby we acquire concepts. But they were not troubled by the sorts of doubts about knowledge which were later to haunt sixteenth- and seventeenth-century philosophers and theologians. However, half a millennium earlier, Augustine did deal explicitly with sceptical problems. Since he was one of the most important Fathers of the Latin Church, his discussions were read in the middle ages. And there is every reason to think that Descartes read portions of Augustine. He admits as much in some of his comments. Augustine, unlike the medievals, was well acquainted with one of the classical sources for scepticism, the Academica (45 bc) of Cicero (106–43 bc). While he was apparently not familiar with the much more rigorous arguments of Sextus, he was very concerned to provide some sort of refutation of Academic scepticism. To that end we find in a number of places passages which sound Cartesian, that is they sound a bit like Descartes’s famous cogito ergo sum (I think therefore I am) – which will be discussed below. In his City of God, Augustine writes: “If the [sceptics] say ‘what if you are mistaken?’ well, if I am mistaken, I am. For if one does not exist, he can by no means be mistaken” (Bk XI, ch. 26). Somewhat similar points are made in, e.g., On the free will (Bk II, ch. iii, § 7), and in his Treatise on the holy trinity (Bk XV, ch. xii, § 23).

It was only, however, at the end of the medieval period and the emergence of the Renaissance that genuinely sceptical difficulties began to emerge. One reason may have been that during the high middle ages, a decision procedure was built into the Church. Councils plus the Pope could deal with problems. Perhaps as Jewish and Islamic questions began to occupy the minds of scholars, debates began which were not totally enclosed by Christian thinking. Throughout the middle ages, at the very least from the time of the First Crusade (1096), the Church increased its pressure on Jews, culminating in the activities of the Inquisition, especially in Spain, in the fifteenth century. If the suppression of Jews and Moslems was to succeed, knowledge of their doctrines had to be obtained. Yet knowledge of their ideas and customs could prove dangerous to Catholic orthodoxy. Those dangers were to materialize in subsequent years.

The decline in the role of the scholastics went hand in hand with the intellectual excitement of the Renaissance, the recovery of Greek and Latin learning thanks to such scholars as Erasmus of Rotterdam (1467–1536) and the development of the New Humanism by a range of scholars, such as Marsilio Ficino (1433–99), who, like many Florentines, much preferred Plato to Aristotle, and who were open to Arabic and Jewish (especially Kabbalistic) learning. There were other major figures such as Savonarola (1452–98), who was executed by the Church. He was in turn an influence on John Pico della Mirandola (1463–94) and his nephew John Francis Pico della Mirandola (1469–1533). All three took seriously the arguments of the Greek sceptic, Sextus Empiricus (fl. 2nd century ad). The goal of their reintroduction of Sextus Empiricus and his Pyrrhonism, as that form of scepticism was known, seems to have been primarily religious. If one used the arguments of Sextus properly, one could cleanse the mind of human pride and arrogance. Such a cleansed mind would then be open to God’s installation of the Christian faith without the many stumbling blocks which philosophical talk traditionally introduced. Their goal was thus to use scepticism to prepare one for the acceptance of the Christian faith, but a faith unsullied by philosophical considerations. Most philosophers and theologians who utilized Pyrrhonism in the centuries that followed were not interested in the goal Pyrrho (about 360–270 bc) set for his movement (that is putting things too dogmatically! He would not have agreed that he was founding anything!), namely, a way of life. Those who proposed fideism, that is the appeal to pure faith, took Pyrrhonism solely as a preparation for faith, not something that was good in itself, and certainly not as a way of life. Savonarola and the Picos were proposing a route via Pyrrhonism to the Christian way of life.

A relatively small number of philosophers had been acquainted with Sextus through manuscript sources in, e.g., the fifteenth century but, as Luciano Floridi has been establishing in his recent work, more than had previously been known. The difficulty in gauging Sextus’s influence in the (early) Renaissance is that while he affected religious concerns in a quiet way, there was a lack of interest in the anti-theory of knowledge function of Pyrrhonian arguments.5 The dramatic quality of Sextus’s influence came only in the second half of the sixteenth century when his arguments were directly applied to claims to knowledge in the context of scientific matters. Cicero’s Academica also gradually became better known. Sceptical ideas and arguments were much more widely disseminated with the publication of the writings of Sextus in Latin translation in 1562 and 1569. A less technical source – and one written in French – was Michel de Montaigne (1533–92). His father was Catholic but his mother was from a Jewish “New Christian” family, i.e. from a Jewish family which had been (usually forcibly) converted to Catholicism under the Inquisition. She, like a number of New Christians who managed to leave Spain or Portugal, became a Protestant. The author of scores of essays and still ranked as a world-class literary figure, the longest of Montaigne’s many essays was on sceptical themes. One theme was the application of sceptical arguments to perceptual and knowledge claims. Another was the use of Pyrrhonism in the context of religious faith, specifically on the use, already noted, of scepticism as both a bulwark against the role of reason in religion and also as a defense of pure faith, matters which increased in importance as the Reformation’s impact spread across Europe. This essay, The Apology for Raymond Sebond (1580 ff), wraps up the many technical arguments of Sextus in a delightful collection of extraordinarily lively and amusing tales. He culled many stories from classical sources about the intelligence and morality of animals, usually by way of contrast with human behavior. The animals generally come out ahead! Sextus Empiricus and Pyrrhonism appear in the text. And on the ceiling of his Library, some fifty-seven sayings or sentences are etched into the beams. Most (19) are from the Bible; the next largest number (12) are from Sextus Empiricus. And as noted, in the text of the Apology, Montaigne uses Pyrrhonism in support of religion:

[Pyrrhonism] presents man naked and empty, acknowledging his natural weakness, fit to receive from above some outside power; stripped of human knowledge, and all the more apt to lodge divine knowledge in himself, annihilating his judgment to make more room for faith … [One thus becomes] humble, obedient, teachable, zealous; a sworn enemy of heresy … He is a blank tablet prepared to take from the finger of God such forms as he shall be pleased to engrave on it.

About Aristotle, he says: “The god of scholastic knowledge is Aristotle; it is a religious matter to discuss any of his ordinances.” Nor is he happy about the Academic sceptics and their acceptance of probable judgments. He presents an objection which the ancient Pyrrhonians had made: “How can they [the Academic sceptics] let themselves be inclined toward the likeness of truth, if they know not the truth?” All of the sceptical arguments against claims to truth can, Montaigne believed, be revised to be directed against claims to be “probable.” But his favorite arguments are to notice conflict cases where a criterion is called for in order to decide between, say, one sense and another, or between sense and reason. Following Sextus (Outlines of Pyrrhonism, II, vii, 75), he also gives currency to a problem which not only carried forward to Descartes, but from Descartes on to Bayle and Berkeley. He poses a fundamental challenge to theories that speak of a resemblance between our perceptions and objects in the world.

The conception and semblance we form is not of the object, but only of the impression and effect made on the sense; which impression and the object are different things … As for saying that the impressions of the senses convey to the soul the quality of the foreign objects by resemblance, how can the soul and understanding make sure of this resemblance, having of itself no communication with foreign objects? Just as a man who does not know Socrates, seeing his portrait, cannot say that it resembles him.

Further, how does one decide such matters as which senses should have priority over others, what is the criterion in such cases, or who can then serve as the judge in disputes, etc. He rehearses the traditional Pyrrhonian questions about “deceptions” as when one has the report of one sense apparently in conflict with another. Although a stick in water appears bent when it crosses the surface, if our hand holds the stick at the same time, it feels straight. These and similar apparent anomalies suggest that given the existence of such so-called “variations in sense experience” it seems impossible to get behind appearances to locate the real things. He also challenges the role of reason, thereby casting doubts not only on the senses but also on the soundness of reason and on science and geometry. And of course appeals to the criterion argument are omnipresent, like traps for the unwary. A generation or so later, i.e. by Descartes’s time, the intellectual atmosphere was saturated with sceptical arguments.

Writers in the sixteenth, seventeenth and eighteenth centuries were not inclined to document their sources. Their texts seldom contain many footnotes. But nevertheless both Montaigne, and his adopted son, Canon Pierre Charron (1541–1603), were significant influences on Descartes and are mentioned by him. Charron produced a systematic version of Montaigne’s sceptical arguments and much enhanced the importance of his scepticism and his reliance on pure faith in matters of religion as well as his scepticism with regard both to reason and sense experience. His De la sagesse [“Wisdom”] (1601) was a widely read and frequently reprinted book. However, the intellectual turmoil which characterized the sixteenth century was not merely a function of the forces unleashed by the Renaissance but more importantly, as Montaigne maintained, by the Protestant Reformation. Nevertheless, Montaigne’s importance for the history of modern philosophy can hardly be over-estimated. He set the stage for developments in seventeenth-century philosophy. He was not only a direct influence on Descartes, but he presented the scepticism of Sextus not simply as part of a preparation for faith, but also – and this proved of crucial importance – as a systematic challenge to philosophy and science.

It is a mistake to think that the Protestants who had to take up the challenge of scepticism were especially anti-scholastic. Their own writings were often dominated by scholastic philosophical ideas and methods even as they attacked the Catholic Church. This should not surprise us. Universities are very conservative institutions and moves away from scholasticism came very slowly, as Descartes was to discover. The excitement which the Reformation caused arose from something quite distinct. La Flèche had been founded not to be a center of scholastic thought nor to defend medieval ideas but to prepare the young intellectuals they successfully recruited to do battle on behalf of the Church. In other words, colleges (like La Flèche) set up as components of the so-called Counter-Reformation took as their task the equipping of their students with the intellectual tools, rhetorical skills, and acquaintance with the arguments of their opponents which would enable Catholicism to triumph over the Protestants.

The arguments of the Reformers, particularly Martin Luther (1483–1546) and John Calvin (1509–64) challenged the very foundations of the Catholic Church by posing the question: which Church is the True Church? The question had been raised explicitly or implicitly before, but those who had raised it in the past were either marginalized or eliminated. This time, the arguments of the Reformers were taken seriously. The Protestants threw down this challenge: the Roman Church claims to be the arbiter of Holy Scripture and the interpreter of the Christian tradition. By what right does the Church claim its authority as ultimate arbiter? Answer: by its appeal to Holy Scripture. But circular reasoning cannot be avoided, according to the Protestants, since the Church’s authority to interpret Holy Scripture is based on its own interpretation of Scripture.

The position of the Reformers had its own problems since it accorded primacy to the words of Scripture as reflected in each individual’s private conscience. An obvious problem, one which surfaced almost immediately, is how to resolve disputes among the faithful. The primary philosophical issue generated by the Reformation is one which has tormented philosophers from that time onward: do we have a defensible criterion of truth? And we must have a criterion if we are to specify which Church is the True Church. The so-called criterion problem was not a major consideration among the medievals. Aristotle was unsympathetic to sceptical questions and within the medieval world, the Church already had its traditional means for mediating and resolving conflicts. But once the Church’s authority was effectively brought into question by the Reformation, arguments to defend or undermine criteria came to the fore. And a perfect handbook of arguments was found in the texts of Sextus. His methodology was geared precisely to expose the difficulties in establishing a criterion, any criterion.

For those who, like Richard Popkin (1923–), see scepticism at the very core of the rise of modern philosophy, two elements were decisive. The Protestant Reformation challenged the presuppositions, the very foundations, of the Christian worldview. But something else was required. And as Popkin sees it, that was provided by Sextus. It was in Sextus and his Pyrrhonism, rather than the Academic sceptics, that one met with systematic arguments against the criterion, arguments which had no parallel in Cicero. It was Sextus’s Pyrrhonian challenge to the criterion which gave disruptive power to the arguments of the Reformers and their Catholic opponents and thereby gave rise, in large measure, to the intellectual crisis of the seventeenth century and hence to the development, as in the work of Descartes, of a “modern” philosophy which sought to come to grips, in one way or another, with the crisis. The Picos and their comrades did not have to cope with the Reformation. They were less worried about achieving philosophical or scientific truths than they were about religious considerations. It is also true that not every philosopher in the late sixteenth- and early seventeenth- centuries was taken up with the crisis or sought to “refute” the sceptics. Some were satisfied with seeking a modus vivendi and were content with probabilities rather than certainties.

Regarding the criterion, Sextus held that the claim that a proposition is true requires that the proposition be judged to be true in accordance with a criterion. The difficulty seems to be insurmountable: the criterion against which we measure that something is true must itself be known to be true, which means that one already needs to know what is true in order to specify the criterion, but one needs a criterion in order to know what is true. Thus one appears to be faced with circular reasoning. Sextus polishes and hones these and similar arguments. For example, to settle a dispute over perceptual data, a judge is required. That requires someone who is not a party to the dispute. But every human is a party to this dispute. The arguments of the sceptics are often directed at criteria for distinguishing between what appears and what we claim is real, and are thus readily translatable from examining putative claims to knowledge in matters of Christian religious controversy. More generally, Sextus discusses at length problems in logic, mathematics, grammar, physics, and ethics and his techniques were quickly employed in religious polemics.

The original goal of the sceptical methodology in its Pyrrhonian form is to bring one to “a state of mental suspense and next to a state of ‘unperturbedness’ or quietude.”6 The sceptic seeks release from, so-to-speak, the mental cramps induced by dogmatic ideas. But the “arguments,” and Sextus is very careful not to be dogmatic about the certainty of his arguments or even their persuasive powers, are extendable beyond his own text. That is why his texts constitute a mine of devices capable of undermining the (often dogmatic) claims of one’s opponents. The person who has advanced a so-called dogmatic position has a stake in his or her own arguments and the arguments of the sceptic are parasitic upon them. If the sceptic picks apart one’s own argument, if the sceptic finds a flaw in one’s own argument, it is faint comfort to respond by saying: “I don’t have to take your refutations of my position seriously because you refuse to assert the truth of your own arguments.”

The Catholics, who were only too happy to promulgate the sceptical arguments of Sextus Empiricus, initially had the advantage. After all, the Protestants were trying to persuade Catholics to leave their traditional Church because of the errors said to infest it and to join a new Church, one which claimed to be True. Sceptical methodology was the perfect antidote. To join a new Church one should first know it to be the True Church lest one jeopardize one’s salvation, as Montaigne (among others) pointed out. The trouble was that by the middle of the second half of the sixteenth century all parties found that they could play the sceptical game. By what criteria can we decide which book is the Bible, which interpretation of a text is correct, which person is the Pope, etc.? For example, one might grant for the sake of the argument that the Pope is infallible, but one would oneself have to be infallible to know with certainty which person is the infallible Pope. Conclusion: the only person who knows with certainty which person is the Pope is the Pope.7 The Protestants, in turn, might claim that the true rule of faith is Scripture, but that most crucial rule, on which their religion rests, does not itself occur in Scripture! All parties to the religious disputes soon realized that attacks on one’s opponents could be turned against one’s self, except that the combatants often believed their own bases to be grounded not on rational principles but instead on faith and hence not amenable to sceptical attack. In the meantime, the many arguments of Sextus were available for all to see – and to use.

To sum up, I have provided some of the historical background and the philosopical and religious importance of ideas of the great sceptics. I have attributed special influence and importance to Montaigne as well as to the Reformation. These two factors set the stage, so to speak, for the arrival of Descartes on the scene. I shall now show how these ideas became a major topic for Descartes as he assumed the role of slayer of scepticism.